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First of all I think the Bose is OK for me in general, it DOES lack the low punch in bass.
So the first step I am thinking is simply replacing the Bose subwoofer with a better open air sub. i think the stock Bose sub runs on 2 ohm (correct me if I am wrong). anyone have experience with that upgrade? did it make a diff in bass?
If that doesnt work, then i might go with adding an amp just for the sub
note: i do not want to add a sub box in my truck......dont like it taking up space........
First of all I think the Bose is OK for me in general, it DOES lack the low punch in bass.
So the first step I am thinking is simply replacing the Bose subwoofer with a better open air sub. i think the stock Bose sub runs on 2 ohm (correct me if I am wrong). anyone have experience with that upgrade? did it make a diff in bass?
I just measured the Bose subwoofer from my 2013 S6. My car had the free-air subwoofer that was mounted under the rear parcel shelf. Here are some pics of the Bose sub from my car:
I got out my speaker testing kit and did a quick sweep on the Bose subwoofer, and here was the result:
The measured impedance of the Bose sub = 2.7 ohms
In the real-world, we would call this a "3 ohm subwoofer."
For some weird reason, the Fs = 304 Hz.
Fs is the "resonant frequency" for most speakers, the Fs is a point where you don't want to play that speaker any lower because you're driving it to resonance and possibly over-excursion.
Most good subwoofers have an Fs in the range of 20Hz to 40Hz.
I don't know why this Bose sub has an Fs of 304 Hz? But, with Bose, all generally accepted rules of audio seem to not apply.
Since I had the testing kit out, I decided to grab the rest of my Bose speakers from my car and test them, too.
Here are the mid-bass speakers from the rear of the car:
Notice the Impedance (Re) = 1.7 ohms this is a 2 ohm speaker
Fs = 90 Hz strange that the Fs on a mid bass speaker is lower than the sub.
Here is the mid range speaker from the front door:
Re = 3.5 ohms
Fs = 186 Hz
The front door midbass enclosure:
Re = 4 ohms
Fs = 95 Hz
Now, for comparison, I happened to have a JL Audio 12W7 subwoofer driver sitting in my closet. Here is the same speaker test on that sub:
Re = 2.7 ohms
Fs = 28 Hz
THAT is what a subwoofer should look like, by the way. Low resonant frequency, and a smooth impedance curve (blue line).
If that doesnt work, then i might go with adding an amp just for the sub
Not a good idea at all. If a speaker is not generating enough output, changing the amplifier is not likely to improve it very much. Double the power will likely get you less than 3 dB additional output. And that's assuming the speaker can handle 2 times the power, which is not a safe bet with a cheap OEM speaker.
Just take look at the Bose subwoofer, which is 12 inches, next to a JL Audio subwoofer that is also 12 inches.
Which one do you think can take more power?
Besides, by the time you go to the expense of buying a different amp and hooking it up, you might as well buy a new subwoofer because it's not a large additional expense to do so.
note: i do not want to add a sub box in my truck......dont like it taking up space........
You don't need a subwoofer in a box. I'm not running a subwoofer box in my car, and it has a competition-grade audio system in it. In fact, infinite baffle subwoofers can actually sound better than subs in a box. They play deeper than a box can, and also have better control so the bass is can be more detailed.
You could replace the free-air subwoofer in the rear deck with something better. It will require some modifications, however. A wood baffle needs to be constructed to add support to the rear deck, and a lot of attention needs to be paid to dampening the metal surfaces. But it's certainly possible, and there are members in this forum who have done it that way.
Another option could be to fabricate a fiberglass subwoofer box into the right side cubby of the trunk where the mesh net pocket is located. A sub could be flushed in there without taking up any trunk space other than the pocket.
subterFUSE, excellent information!
Your point is well made but to be fair the stock sub is classified as 25cm which is at best a 10" speaker. Still paltry if put side-by-side with a JL 10" no doubt.
It's not going to be as simple as dropping a sub in the stock location, though. You need to dampen the rear deck extensively. Then you'll need to build a wood frame/baffle for the sub to mount to because you don't want to mount directly to the metal surface.
Of course, you'll need to get a line converter and an amp to run the sub. The B&O amp is not going to be good for running anything other than the OEM subwoofer. If you damage the B&O amp it is very expensive to replace. It's just not worth the risk.
subterFUSE, excellent information!
Your point is well made but to be fair the stock sub is classified as 25cm which is at best a 10" speaker. Still paltry if put side-by-side with a JL 10" no doubt.
I just measured the Bose subwoofer from my 2013 S6. My car had the free-air subwoofer that was mounted under the rear parcel shelf. Here are some pics of the Bose sub from my car:
I got out my speaker testing kit and did a quick sweep on the Bose subwoofer, and here was the result:
The measured impedance of the Bose sub = 2.7 ohms
In the real-world, we would call this a "3 ohm subwoofer."
For some weird reason, the Fs = 304 Hz.
Fs is the "resonant frequency" for most speakers, the Fs is a point where you don't want to play that speaker any lower because you're driving it to resonance and possibly over-excursion.
Most good subwoofers have an Fs in the range of 20Hz to 40Hz.
I don't know why this Bose sub has an Fs of 304 Hz? But, with Bose, all generally accepted rules of audio seem to not apply.
Since I had the testing kit out, I decided to grab the rest of my Bose speakers from my car and test them, too.
Here are the mid-bass speakers from the rear of the car:
Notice the Impedance (Re) = 1.7 ohms this is a 2 ohm speaker
Fs = 90 Hz strange that the Fs on a mid bass speaker is lower than the sub.
Here is the mid range speaker from the front door:
Re = 3.5 ohms
Fs = 186 Hz
The front door midbass enclosure:
Re = 4 ohms
Fs = 95 Hz
Now, for comparison, I happened to have a JL Audio 12W7 subwoofer driver sitting in my closet. Here is the same speaker test on that sub:
Re = 2.7 ohms
Fs = 28 Hz
THAT is what a subwoofer should look like, by the way. Low resonant frequency, and a smooth impedance curve (blue line).
Not a good idea at all. If a speaker is not generating enough output, changing the amplifier is not likely to improve it very much. Double the power will likely get you less than 3 dB additional output. And that's assuming the speaker can handle 2 times the power, which is not a safe bet with a cheap OEM speaker.
Just take look at the Bose subwoofer, which is 12 inches, next to a JL Audio subwoofer that is also 12 inches.
Which one do you think can take more power?
Besides, by the time you go to the expense of buying a different amp and hooking it up, you might as well buy a new subwoofer because it's not a large additional expense to do so.
You don't need a subwoofer in a box. I'm not running a subwoofer box in my car, and it has a competition-grade audio system in it. In fact, infinite baffle subwoofers can actually sound better than subs in a box. They play deeper than a box can, and also have better control so the bass is can be more detailed.
You could replace the free-air subwoofer in the rear deck with something better. It will require some modifications, however. A wood baffle needs to be constructed to add support to the rear deck, and a lot of attention needs to be paid to dampening the metal surfaces. But it's certainly possible, and there are members in this forum who have done it that way.
Another option could be to fabricate a fiberglass subwoofer box into the right side cubby of the trunk where the mesh net pocket is located. A sub could be flushed in there without taking up any trunk space other than the pocket.
Absolutely fabulous data reference points!!! I love it.
I added a ported box with 2 x 10" JL subs running on a 500 watt amp. The C7 has a huge trunk and there are many boxes made out there that take very little room. I have a manual sub control by my beside my steering wheel.
The premium factory sound was laughable in my opinion, and I disconnected the the stock sub. Unless you want to shell out the dough for custom fabrication enclosure of the sub, a box is the way to go.
so basically is pretty useless to use the stock BOSE amp and just replace the sub by itself. I would need to tap a line input and hook it up to an aftermarket amp and then a decent sub to really make a diff
12-28-2015, 06:58 PM
Bose subwoofer upgrade
